The researchers found that, during the study period, 21% of patients died and 21% had cardiovascular hospitalizations. The five-year all-cause mortality rates were strongly predicted by both serum ferritin and sTfR, independent of other variables (including hemoglobin, measures of renal function, inflammation, and neurohormonal activation). The relationship between sTfR and mortality was exponential (adjusted hazard ratio [HR] per 1 log mg/L, 4.24; P=0.01), while a U-shaped relationship was seen for ferritin and mortality (for the lowest and the highest quintiles vs. the middle quintile, respectively: adjusted HRs, 7.18 and 5.12).

"Both low and high serum ferritin (possibly reflecting depleted and excessive iron stores, respectively) along with high serum sTfR (reflecting reduced metabolically available iron) identify patients with type 2 diabetes and CAD who have a poor prognosis," the authors conclude.

Several authors disclosed financial ties to the pharmaceutical industry.